Haulage machines, e.g., trucks, are used in connection with work sites, such as excavations, surface mines, and construction projects, to receive loads from a loading machine, such as an excavating or mining machine, and then transport those loads to another location. For example, one or more machines such as hydraulic excavators (HEX), wheeled or tracked loaders, electric rope shovels (ERS), etc., may be employed at a work site to excavate or remove material. A plurality of trucks, for example a fleet of trucks, may be used to transport the material away from the area being mined or excavated. Trucks may move to the area, for example along one or more haul roads, and they may queue up and sequentially move into position to receive a load from the excavating or mining machine.
Often the loading machine that is excavating or removing material may remain at the same location, or substantially so, while nominally repositioning itself to load a truck that has moved into position to receive a load from the machine. The excavation may develop somewhat gradually while trucks move to the work site, sequentially receive loads from the loading machine, and move away from the work site to transport the load. Optimally, one truck should be ready to move into position to receive a load as soon as another truck has moved away with its load and the machine is ready to deposit another load. At times, particularly at a large excavation site or mining operation, multiple machines may be operating to remove material while a substantial fleet of trucks operates to receive material from them and haul it away.
When locating or spotting a truck near a loading machine, the most common way for a loading machine operator to signal a truck operator when to reverse into position to receive a load of material is referred to as a “hanging bucket.” The truck operator uses the hanging bucket as a guide to maneuver the truck to the correct position. The truck operator must take great care to move the truck to the correct position and orientation so that the loading machine operator can efficiently load the truck and position the material in the bed correctly.
Careful movement to the correct position also is desirable in order to avoid spillage and to avoid accidents such as collision with the bucket or another part of the excavator and/or with another truck that may be maneuvering to receive a load. Many of the haulage machines (i.e., trucks) employed at large mining/excavating sites are very large and difficult to maneuver, particularly when moving in reverse to a precise location. While an ERS can move the shovel forward or aft of the truck to some degree if the truck is not precisely positioned, precision is more necessary with a HEX since movement of the boom, stick, and bucket are more limited. Where the loading machine operator cannot load efficiently or position the material in the bed properly, the loading machine may request that the truck operator reposition the truck. Repositioning a truck in a mining operation is undesirable since it wastes time.
Where a truck operator requires multiple attempts to properly locate the truck at the optimum loading spot location, both time and fuel may be wasted during a renewed effort to maneuver to the correct location. Repositioning the excavator relative to the truck is generally a much slower, more impractical, and more dangerous procedure. It would be both beneficial and desirable to improve efficiency in the process of loading trucks at work sites such as mines and excavations, for example. There is a need for improvement in the process of spotting or positioning trucks for loading and ensuring that sequential loading of multiple trucks occurs with optimum fuel and time efficiency and with minimal risk of accidents.
One truck loading system is disclosed in U.S. Pat. No. 8,862,390 issued to Sugawara, et al. on Oct. 14, 2014 (“the '390 patent”). The '390 patent discloses a system employing GPS whereby a target position image and an approach route leading to a loading position adjacent an excavator are displayed on a dump truck display when the truck approaches the loading position. A current position image advances along the approach route to the target position image, and the truck is moved into the loading image target position. The '390 patent discloses that the excavator sends a request for movement to the loading position to all dump trucks, but priority is given to the one dump truck closest to the excavator, or to the dump truck with a driver having a high level of skill.
The truck loading system of the '390 patent may enhance loading operations at a work site to some extent, but there remains room for improving loading and material transporting efficiency. While the '390 patent discloses giving priority to either the dump truck closest to the excavator, or to the dump truck with a highly skilled driver, this may not be enough to ensure optimum efficiency. Where multiple loading positions are possible, for example plural excavators that are closely situated or excavators positioned to load from either side of the excavator, simply choosing the truck closest or with a better driver does not consider the orientation of the truck. For example, given size and maneuverability, a closest truck may not be positioned and ready to quickly move into loading position. In addition, giving priority to the driver presumed to have a high level of skill may not adequately reduce risk of accidents.
The disclosed method and system for positioning a truck for loading is directed to overcoming one or more of the problems set forth above.